I thought I would post this video of a talk given by Tim Palmer. The basic message is that climate change is neither a hoax, going to be catastrophic, or going to be benign (Lukewarm). What climate science can (and does) provide is a quantifiable risk of various outcomes, from relatively benign to catastrophic. In my view, a key point is that this depends both on how sensitive our climate is to external perturbations, and on our future emission pathways.

What I found particularly interesting in the video (which is where it’s set to start) is a demonstration of that even though the system is chaotic, we can still estimate the response to an external forcing. If a system is chaotic, then it is very sensitive to initial conditions. This makes it difficult to precisely determine a future state. If, however, we know the range of possible states, then we can also determine how some external influence might bias the system so that it preferentially ends up in certain states, rather than others. Therefore, even though our climate is chaotic does not mean that we can’t estimate how it will respond to external perturbations (in this case, typically referred to as external forcings).

At around 30 minutes there is also a discussion of energy balance models and why we shouldn’t necessarily trust their lower climate sensitivity estimates. The basic argument is that we haven’t yet doubled atmospheric CO2 and so these estimates will likely miss some of the non-linearity in the response. I would argue that this is on top of them not even ruling out – with high confidence – higher climate sensitivity values. Anyway, I’ll stop there. The video is below.

120 Responses to Catastrophe, hoax, or just “Lukewarm”?

I’m not sure how someone can have a realistic view of the (Charney) sensitivity (realistic being greater than 2, most likely greater than 2.5, and a somewhat nebulous upper bound we will say is likely less than 4) and also be a lukewarmer. Three degrees C of warming is definitely going to be catastrophic for some people. I guess he doesn’t believe the WAIS can collapse in anything shorter than many thousands of years.

One of the people I admired most when I first started reading blogs was Mosher as well, JCH.
Can you explain this AMO thing a bit more at some stage? It seemed to be hot during the 40’s pause, cold through the 90’s rise and warm during the recent interlude of rapid rising that did not go up very much. What gives?
If it does go negative we might go through the roof.

Which is, when the PDO went down, the GMST sooned changed direction and it went down; when the PDO went up, the GMST soon changed direction and it went up; when the PDO went down, the GMST soon changed direction and it went down; when the PDO went up, the GMST soon changed direction and it went up; when the PDO went down, around 1983, the GMST kept going up because the level of CO2 in the atmosphere had become high enough to break the natural cycle (I would say the actual break took place around 1952.

Clouds changed around 1983… Eastern Pacific went cold for 30 years. Around 2013 this flipped… Eastern Pacific has been hot as hell ever since. We’re in a heatwave, and so far there is nothing observations that indicates it is about to end.

From NOAA’s prolonged pause paper:

…The synthetic series in Fig. 5a also show examples of greatly accelerated warming lasting a decade or more, which are evidently spring-back effects as an internal variability cooling episode is followed by a strong internal variability warming episode. The strong warming episodes are further amplified by the underlying forced warming trend. One extreme example shows a warming of almost 1 °C in 15 years—a much greater 15-year warming rate than has occurred in the observations to date (red curves). These spring-back warmings illustrate another important potential consequence of strong internal multidecadal variability as simulated in CM3, and reinforce the need to better understand whether such internal variability actually occurs in the real world. …

In short, if CM3’s internal variability is realistic, there is some chance that a rapid underlying warming rate of 0.2 K decade−1 could be ongoing as of 2015, but that this warming signal has been substantially masked (and may continue to be masked for even another decade or more) by an internal variability cooling episode. …

2016 La Niña possibly hotter than the 1998 El Niño… odds of a 2017 El Niño now at 50%, and climbing. 4th hottest year in a row now a possibility. Heatwave.

Can someone help clarify something for me –
People/politicians/scientists spend all this time talking about climate response, when it seems to me, they are actually talking about temperature response.
As though that number tells us everything.

What does that figure actually tell us about our Earth’s biosphere’s response,
or societal response?

What about other critically important parts of this equation?
What about extreme weather response to temperature?
How about societal responses (or lack thereof) to weather driven infrastructure destruction?

Seems to me in our collective obsession over achieving ultimate accuracy we’ve lost sight of those critical cascading consequences.

citizen,
I think they’re using the temperature as a proxy for climate. It can be somewhat problematic given that the how global warming will influence the climate will vary from region to region. I suspect one problem with this is that if you try to talk more and more about regional responses, you end up relying more and more on models, and then you get the whole “models have failed” response. Additionally, even though the regional response will vary, addressing climate change (or reducing the risks) requires reducing global emissions (i.e., what’s ultimately important is the global emissions, not the regional emissions – although, all the regions together, they make up the global emission).

you try to talk more and more about regional responses, you end up relying more and more on models, and then you get the whole “models have failed” response.

Palmer talks about a grant submission to the EU for a supercomputer that he hopes will allow greater skill in predicting at the regional level. Since the talk was given in December 2016, and the awards were, I think, to be announced “the next day”, does anyone know whether his application was successful ? This page rather suggests that he was not (inference by absence)

@-citizenschallenge
“Seems to me in our collective obsession over achieving ultimate accuracy we’ve lost sight of those critical cascading consequences”

The critical cascading consequences will only happen if there IS a change in global temperature. Knowing the magnitude with some accuracy of the temperature change can give some indication of the magnitude of the impacts on extreme weather, the biosphere and societal response. It is used as a short-hand metric for the expected severity of the consequences.

However the local, biological and societal consequences are very difficult to predict without much better computer models as explained in the Video linked in this post. Several orders of magnitude improvement in resolution is required before the global temperature change can be refined into local or extreme event impacts.

Its Murphy’s Law of Thermodynamics. There are infinitely more ways things can get worse than get better.

VRJH, I was using equation loosely. As for your link, BINGO. “Nasa-funded study: industrial civilisation headed for ‘irreversible collapse’?” Place that next to arguing over fractions in the rate variations. ~ regarding obsession with accuracy, of course I understand the demand for that among climate scientists otherwise you’d be pumping out gibberish that didn’t reflect anything.

The challenge is putting that accuracy into a realistic perspective.

izen writes – “The critical cascading consequences will only happen if there IS a change in global temperature. Knowing the magnitude with some accuracy of the temperature change can give some indication of the magnitude of the impacts on extreme weather, the biosphere and societal response.” `
“Some” being the key word. The “slow down” is a thing measured in small fractions.
Besides what was it that slowed down? As for probable consequences, look at the link above, we have more than “some” idea of the coming upheaval regardless of a few tenth of a degree.
____________________________________________________________

Let me run this by you, my working assumption is
the first order cause of increasing ‘global’ warming is the increased atmospheric insulation, caused by increase concentration of GHG. Behavior of these gases in our atmosphere is understood in exquisite detail. This is what causes our climate system to warn, this warming is directly correlated to the amount of GHGs in our atmosphere and happens 24/7/365.25.

Going from that assumption, a decrease in the rate of “measured” surface warming, must mean that the heat is moving into another reservoir and that we haven’t been able to track it with 100% coverage.

Still the bottom line is that our planet’s virtually closed climate system continues accumulating that heat – the rest is an observation and accounting question.

I understand scientists are between a rock and hard spot, if the scientists weren’t obsessed with striving toward absolute accuracy, we’d still be driving carriages around. But, when communicating with laypeople . . . . .

..and Then There’s Physics says: March 1, 2017 at 4:53 pm
“I think they’re using the temperature as a proxy for climate.”
Sure. I think that’s the problem.
My point is that they don’t make clear how little we know about that connection. Of course it’s a proxy, but no one has a clue what kind of proxy beyond, bad, very bad and end of days. (The problem isn’t the striving for accuracy I’m bitching about, it’s the unexplicated over-importance given to those numbers we don’t understand.). Jezz, doesn’t the rough trend tell us more than enough.

It’s like all this drama about 0.0 accuracy because it will give us an indication of the intensity of future climate change??? How will it do that?

We already know increased atmospheric moisture, even the tiny increase witnessed over past half century is causing increasingly devastating downpour events, with nothing but more and worse to come. How much worse who knows. But we do know for certain it will continue and get more intense. What difference will a half degree make in ten years (as opposed to 20 or 30) to Jet Stream disruption? etc. etc..

JCH
Atlantic Multidecadal Oscillation according to the methodology proposed by van Oldenborgh et al.
Atlantic Multidecadal Oscillation index computed as the linearly detrended North Atlantic sea surface temperature anomalies 1856-2013. at Wiki.
Neither match the Tsonis graph you show
You say “Everything you need to know about the AMO is in this Tsonis graph:”
But only talk about the PDO.
“Which is, when the PDO went down, the GMST soon changed direction and it went down; when the PDO went up, the GMST soon changed direction and it went up; when the PDO went down, the GMST soon changed direction and it went down; when the PDO went up, the GMST soon changed direction and it went up; when the PDO went down, around 1983, the GMST kept going up”
I presume the graph is PDO, unstated, and that you feel it matches the temperature changes , which it does, whatever it is a map of.
My question was “Can you explain this AMO thing a bit more at some stage?”
Being in reference to a recent comment on AMO you made elsewhere which I assumed was serious. Sorry but I am completely lost unless you were just joking?

Catastrophic? You decide. The atmospheric concentration of carbon dioxide is now 400 ppm. The previous time that it was so high was during the mid-Pliocene when the global temperature was about 2 °C, or more, warmer than now. Also, the sea stand was about 25 meters higher than now. So if carbon dioxide levels remain that high, at equilibrium, those temperatures and sea levels will once again prevail.https://en.m.wikipedia.org/wiki/Pliocene_climate

Let me try this one again:
My working assumption is
____________________________________________________________

the first order cause of increasing ‘global’ warming’ is the increased atmospheric insulation, caused by increase concentration of GHG. Behavior of these gases in our atmosphere is understood in exquisite detail. This is what causes our “climate system” to warm, this warming is directly correlated to the amount of GHGs in our atmosphere and happens 24/7/365.25.

Going from that assumption, a decrease in the rate of “measured” surface warming, must mean that the heat is moving into another reservoir and that we haven’t been able to track it with 100% coverage/accuracy.

Still the bottom line is that our planet’s virtually closed climate system continues accumulating that heat – the rest is an observation and accounting question.
_______________________________________________

citizen,
That’s roughly correct, but I would maybe finesse the middle paragraph a little.

The climate system is, however, very complex with most of the excess energy going into the oceans. Therefore, a decrease in the rate of “measured” surface warming, does not necessarily mean that global warming has slowed, as it could simply mean that the energy is moving into another reservoir and that we haven’t been able to track it with 100% coverage/accuracy.

”
Still the bottom line is that our planet’s virtually closed climate system continues accumulating that heat – the rest is an observation and accounting question.
”

Probably not accurate to refer to the Earth’s climate system as a ‘virtually closed’ one.
It is closed if one considers energy transport by conduction and convection – but definitely not closed when considering radiative processes.

On an annual basis, the amount of energy available to Earth as a whole from the Sun is about 5.46×10^24 Joules at top of atmosphere. Were the Earth in equilibrium, it would radiate the same amount of energy per year. But the Earth is not in equilibriumdue primarily to rapidly increasing atmospheric GHGs.

Lukewarmers in my limited experience of discussing the position in depth, seem to hold that the warming will not be as great as the worst projections. Or if it is, that will prove to be within the range of variation to which human society can adapt. While science may be invoked to justify this, (N Lewis, low sensitivity, historical resilience) I think the position may come from a deeper belief about the Natural world. The principle of uniformity seems to be underlying much of the lukewarmer position. That there is variation, but as anyone reflecting on their own personal experience can testify, It all stays about the same, just cycling round. It is Hutton’s, “No vestige of a beginning, no prospect of an end.” internalised into a reassuring sense that whatever scientists may claim about radiative energy transfer in the troposphere, the world will continue pretty much the same as it always has during their lifetime, and in fact as far back as human history has reliable written records.

While there is much discussion of tribal affiliation shaping lukewarmer views, I think one reason scientific arguments for more severe climate effects fail is because they do not address the a prior belief that the Earth climate, at least on Human timescales, is essentially unchanging.

If events make it evident that climate change is not as benign as the lukewarmers hoped. That extreme events and impacts on the biosphere are a serious threat to the stability of society, then Lukewarmers will probably respond in one of two ways.
They will get pragmatic, concede it is worse than they thought, and move towards the catastrophists. Or they will refuse to believe the evidence and may even start to move into the ‘hoax’ camp.

However, suppose events indicate that things are NOT quite as bad as the most ‘alarmist’ of the catastrophists predict. That the NASA paper is just another retread of the Spengalian history cycle meme. That the impacts are lighter than the worst projections and the biosphere and human society turns out to be much more adaptable and resilient than ‘worst case scenarios’ had indicated.
Most would be relieved I think.
But I suspect that there would be a contingent who would refuse to accept that AGW will not result in satanic abuse, widespread extinction or rapid civilisational collapse.

Beware of regrets that things may not be SO bad, because it makes your opponents less wrong!

The Very Reverend Jebediah Hypotenuse says:
Probably not accurate to refer to the Earth’s climate system as a ‘virtually closed’ one. definitely not closed when considering radiative processes.
–
“On an annual basis, the amount of energy available to Earth as a whole from the Sun is about 5.46×10^24 Joules at top of atmosphere.”
Thanks for this figure, I looked everywhere to confirm this, no luck.Using it gives.
–
“The rate of energy accumulation is about 8 x 10^21 Joules per year. Equivalent to about
4 Hiroshima atomic bomb detonations per second. Most of that energy goes into the oceans.”
Hiroshima atomic bomb 15 kilotons or 63 terajoules [63×10^12 joules] , respectively.
So 256 x10^12 joules per sec= 8X10^21 joules per year, tick.
So the earth accumulates 2x 10^9 Atomic bombs a year which makes us 0.012C warmer a year.
We get hit with 1.375×10^12 Atomic bombs a year to keep our globe at a balmy 14C.
and 1.374×10^12 Atomic bombs go out a year.
So we are accumulating energy at the rate of 1/1000 of that coming in and we can measure that that precisely?
I think not.
What we are doing is predicting is that the extra CO2 must trap that much more heat per year by known physics and CP2 levels.
What is actually trapped what with solar variation and cloud cover is not known.
The heat response that should be there is not there. Hence the fallacious missing heat argument of the skeptics?
–
“4 Hiroshima atomic bomb detonations per second” Yes, not very impressive compared to the number in the overall everyday turnover.
” Most of that energy goes into the oceans.”. One excuse or explanation.
We just do not know.
Higher cloud albedo, it could just go back into space.

So, to paraphase angech, in energy budget terms, the energy accumulated due to AGW is only about 1/1000th of the total energy reaching the planet from the sun. This implies that anthropogenic global warming is 3 orders of magnitude less catastrophic than the appearance of a second sun in the sky. Thank god for that!

And, if this is not comforting enough, there is the additional bonus that angech is personally not convinced that scientists can measure an energy input so piddling it is only 1/1000 of the Earth’s energy input from the sun.

At around 30 minutes there is also a discussion of energy balance models and why we shouldn’t necessarily trust their lower climate sensitivity estimates.

Ask the planet what it ‘thinks’.

Since the start of the Industrial Revolution about two and a half centuries ago we’ve raised the atmospheric CO₂ concentration from 280 ppm to 400 ppm (in round figures). That’s 120 ppm increase. During the same interval mean global temperature has increased by 1.2 °C. Fitting a logarithmic response to these figures gives a temperature increase of 2.33 °C per doubling of CO₂.

This would appear to be the very minimum figure for warming per doubling: such assumes that this value as derived is actually the equilibrium climate sensitivity. Of course, this figure is not the ECS because it takes decades to centuries after stabilisation of emissions to realise a temperature equilibrium. Rather, this value is closer to the transient climate response, especially given that most of the emissions of CO₂ have only occurred in the last few decades.

Let’s for a moment assume that it is near the transient climate response. I’ve recently seen different claims that TCR is 60-80% of ECS. Based on the trajectory of warming to date, with that calculated doubling value of 2.33 °C, the ECS would be 2.9 °C if TCR is 80% of ECS, and 3.9 °C if TCR is 60% of ECS.

And it’s important to note that this is based on the realised warming to date, which has been significantly masked over most of that time by aerosol emissions, and which are now starting to be significantly addressed and which will therefore cease to mask the actual underlying sensitivity to CO₂.

Rotstayn et al (2013) put the masking at approximately half of the realised warming. Let’s be parsimonious and simply ascribe a 0.1 °C mask to aerosol – a mere fraction of what Rotstayn et al (2013) estimate. This still puts ECS at 3.0-4.0 °C, depending on the magnitude of the proportional relationship ascribed to the warming to date compared to it’s concommittent equilibrium climate sensitivity.

3.0 °C is pretty much the absolute lower bound as it assumes the most parsimonious relationship between TCR and ECS, and given aerosol masking it is probably woefully under the mark. And at some stage emissions aerosols will be addressed, if not by voluntary human action then by the collapse of our global society when fossil fuels run out or have damaged climate sufficiently that social cohesion unravels. This puts a future realised ECS probably closer to 3.5 °C. More if permafrost feedback starts to significantly kick in.

These are some BoE numbers. Eventuality will likely be a bit different, but not much, and probably on the bad side as I made conservative assumptions above…

Yeah, it’s going to be “catastrophic”. Locally, regionally, and very likely globally.. “Hoax” is for Breitbart La La-landers and “lukewarm” is for idiots and optimists. There’s no room left for self-deception.

It’s going to be bad, and we simply now have left only the choice of just how bad we’ll make it.

Fitting a logarithmic response to these figures gives a temperature increase of 2.33 °C per doubling of CO₂.

This would appear to be the very minimum figure for warming per doubling: such assumes that this value as derived is actually the equilibrium climate sensitivity. Of course, this figure is not the ECS because it takes decades to centuries after stabilisation of emissions to realise a temperature equilibrium.

Actually, not sure about that. I wonder if what you did here does yield an ECS estimate. Which is why the rest of your numbers seem a bit high.

During the same interval mean global temperature has increased by 1.2 °C. Fitting a logarithmic response to these figures gives a temperature increase of 2.33 °C per doubling of CO₂.

I don’t quite get this either. I think the temperature increase is a bit too much (in the sense that you should probably take the difference between some average at the beginning and end of the time intervals) and what do you mean by fitting a logarithm? Even if you assume a change in temperature of 1.2K with a change in forcing of around 2.3W/m^2, you would get about 1.9K.

therealbernardj: Sad though it is about the beautiful Tasmanian kelp forests, boffins reckon their demise has far more to do with CFCs than CO2.

And the Carpentaria story isn’t all it seems, either. The mangrove forests have been expanding since the 1980s* and the recent one-off dieback wasn’t as bad as some press reports said – ‘A 700 kilometre stretch of mangrove shoreline in the southern reaches of the Gulf of Carpentaria has died’ etc. Dr Duke hasn’t published his paper on the dieback yet but in interviews he has said that 7% of the mangroves along a 700km (sometimes 1000km) stretch of coast were defoliated, either in patches along the whole 700km (1000km) or in big patches at each end. He blamed the dieback on increased salinity due to a weak rainy season** and he (or perhaps another mangrove expert) said that such defoliation isn’t always fatal.

So it didn’t all die and the bits that died might not be dead.

Big mobs of rain lobbed the affected coast last month, one gathers. Someone should go up there and have a jolly good Captain Cook – or, better, pay Dr Duke to do it. (At the end of last year he was a bit spewing that the dieback story hadn’t even netted him extra prawns, let alone pineapples.)

The Very Reverend Jebediah Hypotenuse says:
March 3, 2017 at 4:12 pm So we are accumulating energy at the rate of 1/1000 of that coming in and we can measure that that precisely Yes. Yes we can.
An Oscar for that answer.
A summary of many different assumptions with error bars of up to 30% in some of the assumptions with a take home message of.
CO2 up.
Therefore forcing up.
Therefore whatever the outgoing energy measure we have there must be retained heat.
It is working backwards, not forwards.
You can get whatever answer you want with the retrospectoscope and a liberal dash of estimated aerosols ( up to 70% variation possible).
You need emmisions out measured.
Emmisions in, measured
And the difference between the two, simple really in concept, not doable in practice??

Appeals to authority aside there are many ways of attempting to assess climate sensitivity.
One is emergent from models, does anyone have that overall figure?
How does it compare to the other estimates. Should one knock off a couple of percent due to the non fit with observations.

CMIP5? 3.22 so knock off 0.22 and get 3.0.
So the forcings estimates put into the models dictate this level.
The observations are half this figure.
So we go with the models. Simple.
verytallguy says:
“This would appear to be the very minimum figure for warming per doubling”
Your RF graph seems to be missing GHG effect from short term water vapour in the air.
Should it be in there, it has a large part to play being much more prevalent than CO2.
Why is it excluded?

verytallguy says:
“This would appear to be the very minimum figure for warming per doubling”

Actually, that was Bernard j.

Your RF graph seems to be missing GHG effect from short term water vapour in the air.
Should it be in there, it has a large part to play being much more prevalent than CO2.
Why is it excluded?

Short answer: because it’s a feedback, not a forcing.

Long answer: atmospheric water vapour has a very short residence time, and is exchanged with an effectively infinite reservoir ( the ocean). Its level is set by atmospheric dynamics. If a quantity were injected into the atmosphere, it would revert to the previous level in a matter of days.

Exasperated answer: if you are still asking this sort of question, you have failed to understand the absolute basics. You need to spend more time understanding and less time challenging experts.

One lukewarmer argument is that any impacts from global AGW, especially if ECS is low, will be subsumed and dominated by local variation. The annual, seasonal and diurnnal variations in any specific locality are larger than the trend at the global scale, therefore the trend is a subsidery problem to the adaption required for natural variation.

Obviously it would be nonsense to calculate a climate sensitivity from this local data (~2% of global with the CO2 rise overlaid in red), but for the people living there it may look like all this talk of impacts is less than convincing.

From “The radiative forcing due to clouds and water vapor V. Ramanathan and Anand Inamdar
Center for Atmospheric Sciences, Scripps Institution of Oceanography,
As the previous chapters have noted, the climate system is forced by a number of factors, e.g., solar impact, the greenhouse effect, etc. For the greenhouse effect, clouds,
water vapor, and CO2 are of the utmost importance. the data needed to understand two fundamental issues in radiative forcing of climate: cloud forcing and atmospheric greenhouse effect. Clouds reduce the absorbed solar radiation by 48 W m2 while enhancing the greenhouse effect by 30 W m2 and therefore clouds cool the global surface–atmosphere system by 18 W m2 on average. The mean value of C is several times the 4 W m2 heating expected from doubling of CO2 and thus Earth would probably be substantially warmer without clouds.”
I take these authors to be saying that clouds and water vapor should be considered in Radiative Forcing, not ignored. That they give a negative feedback according to the best science has to offer and that this needs to be taken into account in assessing ECS.
How long something resides in the atmosphere is different to how much stuff is residing at any one time in the atmosphere which is the basis on which RF of the atmosphere needs to be assessed.
Just asserting one can ignore it does not mean one can ignore it.

> One lukewarmer argument is that any impacts from global AGW, especially if ECS is low, will be subsumed and dominated by local variation. The annual, seasonal and diurnnal variations in any specific locality are larger than the trend at the global scale, therefore the trend is a subsidery problem to the adaption required for natural variation.

Kings of coal might be lukewarm to promote this argument because it may amplify the urgency to mitigate. Unless they can also sell that local variations are somehow independent from an overall process. The word “subsume” may deserve due diligence.

I take these authors to be saying that clouds and water vapor should be considered in Radiative Forcing, not ignored. That they give a negative feedback according to the best science has to offer and that this needs to be taken into account in assessing ECS.

They’re talking about the base greenhouse effect, which is a combination of CO2, other GHGs, water vapour, clouds. In this context, clouds are often regarded as a forcing. However, when we pump CO2 into the atmosphere, clouds and water vapour respond to the resulting change in temperature and are, hence, regarded as a feedback, not a forcing. Also, whether or not the cloud feedback is positive, or negative, depends on how it responds to this change in temperature. That the net cloud forcing, when considering the greenhouse effect, is negative, does not mean that the cloud feedback will be negative.

While it seems rather obvious intuitively that a warmer world will have more atmospheric water vapor, and thus positive water vapor feedback, I’ve just listed the first 5 reasons that come to my mind why this might not be the case.

I am not saying that’s what I necessarily believe. I will admit to having waffled on this issue over the years, but that’s because there is evidence on both sides of the debate.

At a minimum, I believe the water vapor feedback issue is more complicated than most mainstream researchers think it is.

I’ll stick with the ipcc. Blog comments are unlikely to narrow the range.

I absolutely agree Steve. All I’m saying is that a simple first pass on what the planet has manifested to date seems to be winnowing out the bottom half of the ECS ranges previously summarised by the IPCC.

A few weeks ago I attended a seminar given by Eelco Rohling. He used the same value for realised warming that I mentioned above, and he noted that, due to fossil carbon combusted to date, we’re inescapably committed to another 0.5 °C. If Eelco’s correct that’s 1.7 °C from ~120 ppm CO₂. Again assuming a logarithmic temperature response to CO₂ concentration, this puts his imputed ECS around 3.3 °C.

I’ll stress again that I’m not trying to constrain the actual value of ECS. All I’m suggesting is that there is a span of previously-suggested values that appear to be no longer consistent with the empirical evidence. I absolutely concede that the relative contributions of forcings and feedbacks that have shaped sensitivity to date may alter as CO₂ continues to increase: I’m simply operating on the parsimonious assumption of a straightforward logarithmic response for the first doubling. Sticking out my neck though, I suspect that somewhere in ARs 6-10 estimations of ECS for the first doubling will converge toward the upper half of the previous ranges.

Vinne Burgoo, I spoke with Norm Duke last year, and he mentioned both ocean warming and rain failure as causes for the die-back. Both are attributable to climate change. Land use and run-off may also have contributed. As far as the salinity issue goes, one of my two Masters projects was a hydrological survey to investigate the possible impact of salinity changes on mangrove dieback. It was actually more complicated than I could tease out in the time I had available, but one thing was obvious – whether it was salinity- or sediment-mediated, or due to other changes in water parameters, mangroves are sensitive to significant excursions from their usual hydrological regime. Their die-back may not be the result of direct death from the altered hydrological milieu, but from attack by Enoplidia or Ptyomaxia, for example, to which mangroves are less resistant in their weakened state. Whatever the pressures though, mangroves are an example of a community that is adapted to extreme diurnal changes in their environment, but which are sensitive to subtle differences in the underlying mean environmental parameters.

On the flip side mangrove expansion and/or species composition alterations are still ecosystem changes, with concommittent ecological impacts. Some impacts may be ‘beneficial’ (depending on how such is defined…), but indications so far are that overall biodiversity is threatened by the warming of the planet.

Getting back to the title of this post, from the point of view of an ecologist it’s impossible to ignore that the unfolding impact of climate change on the Earth’s biodiversity will be now unavoidably be “catastrophic”.

The ECS diagnosed from the historical record may point to a low best estimate, but it could
also simply mean that our forcing estimates are wrong or that sensitivity increases with time. A
lack of knowledge about ERF and our remiss in diagnosing it within climate models are hampering
progress. Improved ERF knowledge will enable much tighter constraints on ECS, and TCR will
help create a robust basis for climate policy decision-making. The way forward is clear, and it
would be a dereliction of duty if future model integrations did not diagnose forcings and were
solely used to determine overall climate response.

Dr Spencer said
“One of the most robust feedback relationships across the IPCC climate models is that those models with the strongest positive water vapor feedback have the strongest negative lapse rate feedback (which is what the “hot spot” would represent).”
The other most robust feedback relationship from the IPCC climate models is of course the emergent ECS.
As ATTP , Skeptical Science and others state
There is a broad consensus that fast-feedback sensitivity is 3°C for doubled CO2. In other words, fast feedbacks multiply the 1.2°C direct warming by two-and-a-half times.
This positive feedback factor is almost entirely due to the assumptions in water vapor GHG effect rather than it’s albedo effect, which comes first, by the way.
Dr Spencer said also” I’ve just listed the first 5 reasons that come to my mind why this might not be the case.I am not saying that’s what I necessarily believe. I will admit to having waffled on this issue over the years, but that’s because there is evidence on both sides of the debate.”

> Spencer said also” I’ve just listed the first 5 reasons that come to my mind why this might not be the case.I am not saying that’s what I necessarily believe. I will admit to having waffled on this issue over the years, but that’s because there is evidence on both sides of the debate.”

Indeed, Doc. I quoted it. You have a point? Mine was that even Roy can at best appeal to #AlternativeTheories, which is a tad weaker than your “best science” sideswipe.

Before rope-a-doping to your next thing, please acknowledge the bit about forcings and feedbacks. If you did not get AT’s memo, you may like this longer version (feat. Senior):

please acknowledge the bit about forcings and feedbacks.
“That the net cloud forcing, when considering the greenhouse effect, is negative, does not mean that the cloud feedback will be negative”
“when we pump CO2 into the atmosphere, clouds and water vapour respond to the resulting change in temperature and are, hence, regarded as a feedback, not a forcing”
I acknowledge that ATTP puts forward this view.
I disagree on his interpretation, hence it cannot be resolved.
If more clouds and water vapor are are formed with a rising temperature, and they happen to block absorb or reflect energy at a higher level, then the total solar irradiance is lessened.
Seeing such mechanisms have been assessed by some higher authorities as having a probable negative feedback then a larger amount of such forcings might, in some skeptic world at least, cause more negative forcings.
To admit such would be heresy as it would make ECS much lower.
It all holds together ECS 3 or greater, AGW , with positive feedbacks. If we cannot even mention the taboo subjects without ridicule, how can we be scientific and prove we are right.

I don’t think what I said was all that controversial. The cloud forcing is the net effect of clouds compared to there being no clouds. The cloud feedback is the response of clouds to a change in temperature. That the former is negative does not mean that the latter should also be negative.

Outside the blogosphere, I can’t think of the last time I had a *logical* dispute with another rational person and did not fully expect that, after the appropriate discussion, one of us would concede that the other was right.

Among rational people, we can agree to disagree on policy/politics, agree to disagree on metaphysics/religion, and other subjective matters, and we can sometimes disagree on scientific matters when the evidence is incomplete because we have different inferential thresholds. But we should expect to get the same answer, eventually, on matters of logic (a few thorny paradoxes aside). Even where the source of disagreement is incomplete evidence, we should at least be able to discuss what evidence we would require before we changed our mind or reached consensus.

That angech could so glibly dismiss the idea that forcing and feedback could have opposite signs, claim this to be a matter of interpretation, and not even try to reach an understanding of what ATTP is saying (or, conversely, try to show ATTP where he is wrong), speaks volumes.

Willard
” And yes.
Paragraphs.”
I apologize for my writing style but it is part of me, I guess. Curiously for someone who likes to think his English is OK, I seem to have a massive blind spot in this regard and an explanation and repost of a particularly bad example at times when I make one might help open my eyes. When I am trying to make several points in a row I do leave a gap to differentiate them with a small hyphen. Is this what upsets people?
Regardless it is my style and it is probably the content more than the writing which is upsetting at times. We all have our blog idiosyncrasies, mine is a bit scattergun which reflects how I think. ideas pour in quickly and I want to get them out and expressed. Having said that a reread and editing might be possible.
“Doc. Please don’t push it.”
Having said that a reread and editing must be essential.
“> some higher authorities”, I meant V. Ramanathan.

I doubt you see the irony of arguing that Palaeo evidence is unreliable because researchers have been able to determine how accurate it is under changing conditions.

But the Paleo evidence that is not open to any doubt derives from ice. That there is a lot still around from the last ice-age, and a lot missing, but the glacier valleys and 20ft of sea level rise since the last maximum.

Ice is unequivocal, If it warms it melts. When it doesn’t melt it can be dated and retains air bubbles that can be DIRECTLY measured giving the actual atmospheric composition. Its isotopic composition gives the temperature of its source.

The amount of ice that melts at the end of the glacial maximum compared to the amount of change in energy distribution from the Sun means you need CO2; and it puts a strong lower limit on ECS.

Over 20 years ago, Ramanathan and Collins (1991 Nature, “RC91”) advanced what became known as the “Thermostat Hypothesis”, relating to how cloud formation over the tropical Pacific warm pool limits just how warm surface waters there can get. While this conceptual view was OK for the warm pool itself, they made some extrapolations which weren’t really warranted about what this meant for the larger-scale climate system, and ultimately whether “global warming” will be reduced by a resulting increase in cloud cover reflecting more sunlight back to space (negative cloud feedback).

Now, I will say that I believe that the climate system is stabilized by negative cloud feedback, even though most if not all climate models exhibit positive cloud feedback. But you have to be careful about what you use as evidence, and cloud formation over warm areas (e.g. at the end of this post at WUWT) is simply not evidence. Even climate models with strong positive cloud feedback (decreasing clouds with warming) are going to form clouds over warm areas of the oceans. That’s the way atmospheric circulation systems work.

I would love to be able to explain Venus but the conditions on earth need working through first.
The physics is the same but the conditions the physics work under and the planetary position, composition and history are all totally different. No comparison should be made.
For one there has been no 4 billion years of life taking in CO2 and turning it into a giant deposit of calcium compounds through 5 to 40 kilometers of Earth crust. There is no skin of water with all it’s unusual properties. There is no moon to alter the dynamics of the skin of water not to mention the crust.
Then there is no runaway CO2 induced warming. There is a normally hot planet for an atmosphere of CO2 that has not been turned into rock by lifeforms. Venus is hot because it is closer to the sun and has a CO2 atmosphere. It has not suddenly warmed up and run away, it has probably been that way for billions of years. Paleo data is sadly lacking.

When did you become the arbitrer of what is, and is not, allowed? The point I’m making is that there is no fundamental reason to think that we’re in some kind of special state and that the system will somehow act to keep us in this state.

Homeostasis. The tendency of the body to seek and maintain a condition of balance or equilibrium within its internal environment, even when faced with external changes. Palaeoclimate variability is due to the rotation of the earth, the elliptical orbit of the earth, Milankovitch, Tides, clouds, water and vulcanism, not to mention the odd asteroid. Homeostasis is simply the tendency of any body to return to normal conditions if the external, and internual changes do not blow it apart. Entropy and physics demand it. Homeostasis is the norm over long time periods when forcings are minor.

[Insert another carriage return. – W]

The planet surface is not the planet surface that dinosaurs walked on but the temperature is much the same.

[Like this. – W]

BBD I like paleontology, I trust the evidence of layered deposits and trying to decipher the past. I am happy to accept that a rough guide of past conditions can be built up from ice deposits.

[And this. – W]

Izen said “Ice is unequivocal, If it warms it melts. When it doesn’t melt it can be dated and retains air bubbles that can be DIRECTLY measured giving the actual atmospheric composition.”

[See? – W]

Obviously if we have a warm spell for 20 or 200 years there will be a gap in the record 20 to 200 years apart ? How could one tell?Unequivocal is a word that should be used sparingly with ephemeral elements. Isotopic composition in ice is not known to be rigorous either.

It has not suddenly warmed up and run away, it has probably been that way for billions of years.

Noone is suggesting otherwise. However, this indicates that there isn’t some special negative feedback that protects against runaway. It’s certainly true that the Earth has probably locked up enough CO2 in rocks that a runaway is extremely unlikely, but we can’t preclude some substantial warming if we continue to pump CO2 into the atmosphere – there isn’t some special negative feedback that will protect us.

You may remeber that in 2012 the very thing you speculate about, happened. A very warm week of weather melted the top of the Greenland ice cap. There was some discussion about just how often it happened. The beauty of ice cores is that it is possible to tell.

paragraph 1. This is a small, self contained section of text. When completed I press the carriage return button twice. That leads on to

paragraph 2. This introduces a second concept or develops that introduced in the first paragraph. Particularly in short blog comments, it’s important not to cover too much in one paragraph. I’ll include some guidance at the end of this comment. Of course, before that, I’ll have paragraph three, after two carriage returns

paragraph 3. I’ve used this one purely to emphasise the point through repetition. Leaving long blocks of text without separate paragraphs renders your meaning obscure, and your arguments lost. We’ll finish with a quotation to an online guide to demonstrate that this is not merely my personal opinion, but is backed by sources:

Long paragraphs wear a reader down. Avoid writing more than five or six sentences in a paragraph before you break. The general rule is that a paragraph should break only when it has completely developed the topic sentence. However, it often takes more than five or six sentences to accomplish that. In those cases, find a logical place to break. On the other hand, many short paragraphs also impede the reader’s appreciation of the material by becoming monotonous and boring. The length of the paragraphs in an essay or a piece of writing is important, and you should pay attention to it. By saving a closing, summary sentence for the end of the development of the topic sentence, you can signal that you are moving on to another idea.

you may also note that in order to ensure quotations are recognised as such, myself and many other commenters highlight, either in italics or as I did above using the “blockquote” tag. To use the tag, employ the “greater than” and “less than” signs instead of the square brackets following.

[blockquote]It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human-induced contribution to warming is similar to the observed warming over this period.[/blockquote]

When “greater than” and “less than” signs are used instead of square brackets returns as

It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human-induced contribution to warming is similar to the observed warming over this period.

Note that throughout this comment I have used two consecutive carriage returns to separate the paragraphs clearly for readability.

Dessler’s claim (and the IPCC party line) is that cloud changes are caused by temperature changes, and not the other way around. Causation only occurs in one direction, not the other.

In their interpretation, if one observes a warmer year being accompanied by fewer clouds, then that is evidence of positive cloud feedback. Why? Because if warming causes fewer clouds, it lets in more sunlight, which then amplifies the warming. That is positive cloud feedback in a nutshell.

But what if the warming was caused by fewer clouds, rather than the fewer clouds being caused by warming? In other words, what if previous researchers have simply mixed up cause and effect when estimating cloud feedback?

“Spencer’s paper”: It didn’t take my colleague Andrew Dessler long to work out a demonstration that Spencer’s new paper is wrong. Many of his colleagues have counselled against publishing this demonstration, arguing that the time wasted refuting yet another in a series of incorrect papers by the same author would be better spent advancing our knowledge about the climate system and that at some point it’s better just to ignore incorrect papers. I personally agree with you that an incorrect paper should be publicly refuted in the scientific literature, but I can see how it would get annoying to be working on one public refutation after another.

He’s already making it painful to read, for the sake of not being bothered to hit the return key. If he can’t be bothered to do that, I would be quite happy to make his contributions even harder to decipher as a quid pro quo.

If he wants to proudly hew to an idiosyncratic style that he knows makes it annoying to engage with, so be it. Carrot and stick.

=={ Homeostasis. The tendency of the body to seek and maintain a condition of balance or equilibrium within its internal environment, even when faced with external changes }==

Indeed.

When I think of homeostasis, I think of a system of stabilization that has developed through multi-generational evolutionary processes whereby species that aren’t able to adapt go extinct. For example, (as with humans) a species that isn’t able by one means or another to stabilize internal temperature within some range when surrounded by a changing external environment, goes extinct.

I have a hard time envisioning such a process when we’re dealing with a planet. I would imagine that planets do “go extinct” in a sense; if they aren’t able to stabilize certain conditions they fall apart or collapse or burn up or something. But there isn’t a process whereby they “evolve” over generations – which would seem to me to be a necessary process for developing a system that maintains homeostasis.

That is, unless you believe in some supernatural power. Do you think that our planet has some mechanism of homeostasis because of the intelligent design of some supernatural power?
.

Joshua,” homeostasis, I think of a system of stabilization that has developed through multi-generational evolutionary processes whereby species that aren’t able to adapt go extinct. I have a hard time envisioning such a process when we’re dealing with a planet”

Agree. The problem is that homeostasis, like so many other things, can be applied to a wide range of topics where the essence of the meaning can vary. Adapt or die, evolution, is not really homeostasis though it may lead to it for some species. Crocodiles and ferns might be said to have remained the same for millions of years. Gaea as the overall expression of life on this planet certainly does not represent the original Gaea.

Some planets are big rocks that survive for a few billion years. Provided they do not get to close to the sun they maintain a homeostasis not by design but due to the laws of physics and entropy,
If we go back another 8 billion years to when they were a part of a previous sun then the concept blurs a little.

Homeostasis here is about the atmosphere and the ability to stay within a temperature range for billions of years. We have gone through 3 or 4 changes in the atmospheric composition since a world with surviving paleontological data [rocks and crust] emerged. I am not sure of the temperature range in prelife conditions other than to assume an atmospheric temperature was reached conducive with life 4 billion years ago and that it must have remained within these parameters on some parts of earth ever since.

Our current atmosphere and surface have qualities [inputs] that determine a status quo. If you like the entropy ball has rolled to the bottom of the hill [I should trademark that] and is unlikely to move very far without a significant input. As ATTP says CO2 may be a significant input and may cause a runaway situation of sorts. Given that the huge bulk of the earth has had a lot of forcings over the years and is at the bottom of the energy hill I expect stability. He is right though in that we do not know what lies around the corner and there may be a significant temp rise. I certainly would never have believed in the power of the atom until someone released it.

Found back one source for NG’s quote above. The comments disappeared from his old blog. Senior still has it. Here’s another bit on Spencer:

Bottom line: I agree with you that cloud feedbacks are the most poorly-handled of all important feedbacks and that the uncertainty is so large that even its sign is unknown. They’d have to be quite negative, though, to negate the other (more precisely known) net positive feedbacks, though, and that is unlikely.

Also, Spencer has recently dropped below my credibility threshold so don’t bother citing him here unless the work is corroborated.

I’m not sure why you feel what you term homeostasis is relevant, as no one is arguing for a runaway. A very wide range of sensitivities is possible within a climate system which does not run away.

It is worth noting that long term runaway has likely happened before in “snowball earth” events, and that ice ages show there is considerable instability to relatively small changes in forcing in the modern climate system.

https://pielkeclimatesci.wordpress.com/2011/09/01/how-scientific-debate-should-be-conducted-with-john-nielsen-gammon/ credibility threshold warning?
“August 25, 2011 at 3:56 pm R Pielke The radiative forcing of CO2 and the other greenhouse gases is a relatively minor warming effect unless there is a significant positive water vapor/cloud feedback. There is significant research that shows that the model simulation of the water vapor/cloud feedback is overstated Sun, De-Zheng, Yongqiang Yu, Tao Zhang, 2009: Tropical Water Vapor and Cloud Feedbacks in Climate Models: A Further Assessment Using Coupled Simulations. J. Climate, 22, 1287–1304
“underestimating the negative feedback from cloud albedo and overestimating the positive feedback from the greenhouse effect of water vapor over the tropical Pacific during ENSO is a prevalent problem of climate models.” At least I am not on my own.

…There is no significant correlation found between the intermodel variations in the cloud albedo feedback during ENSO and the intermodel variations in the cloud albedo feedback during global warming. The results suggest that the two common biases revealed in the simulated ENSO variability may not necessarily be carried over to the simulated global warming.

I don’t mind quotes with quotation marks. I just used Markdown-email style “>”.

But two carriage-returns should be mandatory.

***

Zeke summarizes Dessler’s criticisms of SB11 thus:

Dessler points out that Spencer and Braswell exclude a number of models that do reasonably well at matching observations, and also choose the surface temperature set (HadCRUt) with the largest deviation from models over the period in question. He creates his own chart that shows a much more nuanced picture. He also notes that the models that best agree with observations are the ones that do the best in replicating El Niño events, and suggests that “the ability to reproduce ENSO is what’s being tested [by Spencer and Braswell], not anything directly related to equilibrium climate sensitivity.”

>How’s that working out so far?< I read the whole exchange, very civil, they agreed to disagree. If it were not for Spencer, Curry, Pielke and Lindzen I guess there would not be a discussion. While some people of credential, no matter how disparaged, raise these issues, I guess I can ask why they do so.

angech,
Of course you can ask why they do so. However, it is worth always bearing in mind that they do hold minority views. Even the mainstream position does not preclude these outcomes, they just regard them as unlikely.

(Note the space between the quote and my own comment, Doc. Please stop playing dumb and do paragraphs.)

Perhaps as far as tone self-policing is concerned, but Senior was far from being civil argument-wise. He consistently mismanaged his commitments by injecting talking points and deflecting from NG’s points. Even the discussion was irresponsive to NG’s criticism of Junior’s ink blot:

“If it were not for Spencer, Curry, Pielke and Lindzen I guess there would not be a discussion. While some people of credential, no matter how disparaged, raise these issues, I guess I can ask why they do so.”

Understand this. When you turn away from the science and try to understand motives (why),
you are quite simply turning to a problem that is harder to solve than climate.

Or you could look at it this way, you are trying to solve a hard science problem by appealing to a soft science question.

You are switching from the hard to understand to the harder to understand.

And worse. Nothing you could discover about motives will change the science. So go back to understanding the science. if you cant, then suspend judgement and commenting until you do understand.

And if you find suspending judgement intolerable, if you want an answer about science you cannot understand, then be pragmatic and accept the consensus. On average youll be more right than wrong.

Agree with Mosher here. The correct answer to “why they do that?” is: who the hell should care?

Once you start attempting to assess motives, guess at personal ethical principles, and triangulate on possible IQ scores, you have lost the high-ground. As with Anakin Skywalker, if you continue down that path, you will eventually be lost to the Dark Side of identity politics and pop-psych.

Personally, I mostly avoid the above question by simply no longer reading the silly stuff that Spencer, Curry, Pielke, and Lindzen produce. Over time, I have found that where their blog posts are concerned, the rewards are almost always not worth the time and effort.

Similarly, when Scott Pruitt, the brand-new head of the EPA, can say this with straight face:
”
I think that measuring with precision human activity on the climate is something very challenging to do and there’s tremendous disagreement about the degree of impact, so no, I would not agree that it [carbon dioxide] is a primary contributor to the global warming that we see… We need to continue the debate and continue the review and the analysis.
”
knowing his motives, ethics, or IQ, is not required to determine that he is not fit for the job (except somehow, to Congressional Republicans).

Looking back at angech’s last comment – the one in which he didn’t answer ATTP’s question – it seems to me that he was suggesting only that because there are contrarians, there might be problems with the science.

Not a logical conclusion, I know, but still, that seems to be what he was saying.

The *ulterior* motives – if any – of the players were not actually being brought into play (quite rightly, per Steven, Willard and the Very Rev). So an accidental squirrel, then,

were not for Spencer, Curry, Pielke and Lindzen I guess there would not be a discussion. While some people of credential, no matter how disparaged, raise these issues, I guess I can ask why they do so.

While I agree with Mr. Mosher that “nothing you could discover about motives will change the science”, one can scarcely resist speculating on individual AGW-deniers’ motives. What is one to think, after all, when someone with respectable scientific credentials resorts to conspiracism rather than give up on arguments long discredited by his peers?

We know from the publicrecord that some individuals and families, having amassed billions of dollars selling us fossil fuels at prices that externalize the climate change costs, have invested hundreds of millions in a sophisticated disinformation campaign intended to confuse the public about the scientific case for AGW. It’s not as easy to trace that to financial incentives for scientists, unfortunately, aside from the occasional breathless revelation.

We also know of the Republican Party’s plans, as early as 2002 (h/t Shub Niggurath), to enlist contrarian scientists in support of anti-environmental positions. We’ve seen the success of that strategy, although among the 6% of scientists who admit to being Republican, there are conservative climate scientists who emphatically support the AGW consensus.

A scientist’s motivation for AGW-denial is seldom as simple as either money or ideology, presumably. John Mashey published a proposed detailed taxonomy of AGW-deniers a few years back. It’s an entertaining aid to speculation, if nothing else.

[browser mishap above, please delete…]
I fully support what Mosher was saying, but I think what angech really meant is that he takes comfort from the fact that at least some scientists express AGW skepticism so it is at least plausible, to him, that his world view is consistent with reality. The question of motive doesn’t come into it for him because he assumes that Curry etc are seekers after truth, and truth-seeking is a motive we all understand.

By contrast, I look at what Curry and her ilk produce and I find it strong (but obviously indirect) evidence of AGW . If skepticism were rational, and there really were significant flaws in AGW, then I would expect to see a higher calibre of skeptic. If WUWT, Curry, and so on, are really the main skeptical game, then AGW skepticism is hollow at its core. That is obvious to most of you, but not to angech.

Given how wrong-headed she is, understanding motive for Curry etc is probably impossible, but it seems very likely that part of the explanation is that it is easier for someone with her skill set to make a name for herself and develop a fan base as a skeptic than as a consensus scientist. The required standards are so low. I mean, who would have thought the “no warming since 1998” meme would have produced so much discussion?